1. Field of the Invention
The present invention concerns a radiation converter (transducer) of the type having a luminophore layer formed from needle-shaped crystals applied on a substrate, wherein the crystals are composed of CsI doped with Tl.
2. Description of the Prior Art
Radiation converters are used in imaging medical technology diagnostics. They are in particular used in x-ray image intensifiers, x-ray detectors, and as intensifier foils in x-ray film exposures, in storage luminophore image systems and in cameras. In such radiation converters, high-energy radiation is absorbed and converted into light in a scintillator or luminophore layer. This light is detected by means of photodiodes or CCDs and is evaluated by downstream electronics.
Insofar as alkali halogenides (for example CsI:Tl) are used to produce the luminophore layer, an emission maximum of the generated light according to the prior art typically lies in the range from 540 nm to 560 nm. Contrary to this, a maximum sensitivity of photodiodes and CCDs lies in the range from 500 nm to 520 nm. This leads to a loss of light yield which must be compensated by an undesirable increase of the radiation dose.